Metallizable, scratch-resistant and solvent-resistant film

ABSTRACT

The present invention relates to a coating composition comprising at least one thermoplastic acrylonitrile-butadiene-styrene copolymer in a content of at least 30% by weight of the solids content of the coating composition, at least one UV-curable reactive diluent in a content of at least 30% by weight of the solids content of the coating composition, at least one photoinitiator in a content of ≥0.1 to ≤10 parts by weight of the solids content of the coating composition and at least one organic solvent, where the proportion of ethylenically unsaturated groups is at least 3 mol per kg of the solids content of the coating composition. This is used to provide films and moldings coated therewith, having a metallizable, scratch-resistant and solvent-resistant surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application (under 35 U.S.C. § 371)of PCT/EP2014/063218, filed Jun. 24, 2014, which claims benefit ofEuropean Application No. 13173948.4, filed Jun. 27, 2017, both of whichare incorporated herein by reference in their entirety.

The present invention relates to a coating composition comprising ABSpolymers, and to films coated with this coating composition. Thesurfaces of the coated films are metallizable, and additionally haveexceptional scratch resistance and solvent resistance. The presentinvention further relates to 3D plastics parts comprising the inventivefilm, and to the use of the inventive films for production of plasticsparts in film insert moulding processes.

BACKGROUND OF THE INVENTION

Film insert moulding technology has become established for theproduction of plastics parts in the injection moulding process. Itinvolves first two- or three-dimensionally prefabricating the frontalsurface of a part from a coated film and then filling or insert mouldingit with a polymer melt from the reverse side.

It is often desirable that the front side has sufficient protection fromchemical and mechanical effects. This is often achieved in the prior artby an appropriate coating or paint system on the surface. In order toavoid wet coating of the finished three-dimensional parts, it isadvantageous that such a paint or coating system should already havebeen applied to the film which then runs through all the further formingsteps with the film and is then ultimately cured, for example by UVexposure.

This gives rise to a very specific profile of properties for coatedfilms which suit this technology. In the prior art, the term “formablehardcoating” has become established for this product class, meaning afilm coating which is at first sufficiently blocking-resistant, but thencan be thermally formed as desired together with the substrate and atthe end receives the properties of a protective layer through UV curing.

Such a combination of properties, in the sense of blocking resistanceand thermoplastic characteristics of the primary coating, together withthe great latent potential for UV crosslinking, is difficult toimplement.

Most of the approaches to a solution for this objective in the prior artcomprise the use of macromonomers which are prepared principally bydual-cure processes, as described inter alia in Beck, Erich (BASF),Scratch resistant UV coatings for automotive applications, Pitture eVernici, European Coatings (2006), 82(9), 10-19; Beck, Erich, Into thethird dimension: three ways to apply UV coating technology to3D-automotive objects, European Coatings Journal (2006), (4), 32, 34,36, 38-39; Petzoldt, Joachim; Coloma, Fermin (BMS), Newthree-dimensionally formable hardcoat films, JOT, Journal fuerOberflaechentechnik (2010), 50(9), 40-42; EP 2113527 A1; Petzoldt etal., Development of new generation hardcoated films for complex3D-shaped FIM applications, RadTech Asia 2011, Conference Proceedings.

The insert moulding of these film products with, for example,polycarbonate melt (film insert moulding) results in the desiredplastics parts.

Furthermore, principally for reasons of design, there exists a greatneed to be able to provide those plastics parts which find wide use inautomobiles, in all other modes of transport, in electrical andelectronic devices, in domestic appliances, in sanitary articles, in thefurniture industry and in the jewelry industry with a metal layer suchas, more particularly, a chromium layer. In this way, the advantages ofthe plastic, for example free shaping and low weight, are combined withthe high-quality appearance of metal surfaces. Also of interest arepartially metallized components, with part of the area left withoutmetallization for emblems, scales or viewing windows. These areas haveto meet the high demands on media resistance that are placed on coatedplastics parts, for example with respect to skin creams, cockpit careproducts, solvents, and a certain scratch resistance. Uncoatedthermoplastics, for example the acrylonitrile-butadiene-styrenecopolymer (ABS) which is of very good suitability for the desiredgalvanization, are inadequate in relation to solvent resistance andscratch resistance, measured, for example, by customary demands for theautomobile interior or higher-quality electrical and electronic devices.

The process of galvanization of plastics is described in detail in theliterature, for example in B. D. Rathmann in Chemie in unserer Zeit 15(6) 1981, page 201 ff. and D. Bernd in Kunststoffgalvanisierung in derPraxis [Plastics Galvanization in Practice], Crash Course atKunststoffinstitut Lüdenscheid 2012, Conference Book. It is known in theprior art that the plastics of best suitability for such a galvanizationinclude ABS copolymers. Polycarbonate/ABS coextrusion films, asdescribed, for example, in WO 2012/120007 A1, are in need of improvementin two aspects: As a result of the coextrusion process, ABS layers ofthis kind cannot be thinner than 15-20 μm. At thicknesses of 20 μmupwards, these layers are not as transparent as would be desired in someapplications. Moreover, ABS layers of this kind do not meet the demandsindicated on solvent resistance, and therefore cannot be regarded as aprotective layer for plastics parts, as is actually expected from alayer which forms the surface of the film or of a moulded componentthereof.

For these reasons, there is a great need in industry for coated filmshaving a coating which firstly has adequate blocking resistance forfurther processing after the application and first drying operation, andsecondly has a certain scratch resistance and solvent resistance aftercuring by means of UV light, for example, and is additionally alsogalvanizable. The fulfilment of such a profile of properties with thecombination of properties mentioned constitutes a particular challengeto the person skilled in the art.

BRIEF SUMMARY OF THE INVENTION

It has been found that, surprisingly, thermally formable films havingsuch a combination of properties of the coated surface can be obtainedwhen they are coated with a coating composition comprising at least onethermoplastic acrylonitrile-butadiene-styrene copolymer in a content ofat least 30% by weight of the solids content of the coating composition,at least one UV-curable reactive diluent in a content of at least 30% byweight of the solids content of the coating composition, at least onephotoinitiator in a content of ≥0.1 to ≤10 parts by weight of the solidscontent of the coating composition and at least one organic solvent, andthe proportion of ethylenically unsaturated groups is at least 3 mol perkg of the solids content of the coating composition.

DETAILED DESCRIPTION OF THE INVENTION

The present invention therefore provides the following: a coatingcomposition comprising

-   -   (a) at least one the thermoplastic        acrylonitrile-butadiene-styrene copolymer in a content of at        least 30% by weight of the solids content of the coating        composition;    -   (b) at least one UV-curable reactive diluent in a content of at        least 30% by weight of the solids content of the coating        composition;    -   (c) at least one photoinitiator in a content of ≥0.1 to ≤10        parts by weight of the solids content of the coating        composition; and    -   (d) at least one organic solvent,        where the proportion of ethylenically unsaturated groups is at        least 3 mol per kg of the solids content of the coating        composition.

The inventive coating composition can be obtained in a simple andefficient manner. In addition, it is possible to galvanize coatingsobtainable thereby on many surfaces such as, more particularly, thosefor the films which are candidates in a film insert moulding process asdesired, i.e. to coat them with a metal layer. Surprisingly, the layersobtained with the inventive coating composition additionally haveadequate blocking resistance after drying, can then be thermally formedas desired together with the coated substrate, and receive ascratch-resistant and solvent-resistant surface after curing, forexample by means of UV radiation.

The scratch resistance can be determined, for example, using the pencilhardness, as measurable on the basis of ASTM D 3363. An assessment ofsolvent resistance can be made on the basis of EN ISO 2812-3:2007. It isremarkable that the surface of the moulding obtained by the inventivecoating of the film with the coating composition and final curing by UVradiation has good durability, even with respect to acetone, a solventwhich is otherwise very harmful to polycarbonate surfaces.

Acrylonitrile-butadiene-styrene copolymers, as used in the inventivecoating composition, are thermoplastics commonly known by theabbreviation ABS (DIN EN ISO 1043-1 and DIN ISO 1629). The Vicatsoftening point (ISO 306 VST/B/50 (50 N)) of the ABS copolymers for usein accordance with the invention is preferably around 100° C., morepreferably at least 95° C. Preference is given to ABS copolymers havingan acrylonitrile content in the range of ≥19 and ≤35%, more preferablyin the range of ≥20 to ≤30%, most preferably in the range of ≥22 to≤25%. The proportion of the polybutadiene in the ABS copolymers ispreferably in the range of ≥10 to ≤16%, more preferably in combinationwith the preferred ranges for the acrylonitrile content. The remainderof the respective proportions in the ABS copolymers comprisespolymerized styrene derivatives. Preference is given here to styrene.

ABS copolymers are on the market in large volumes as commercialproducts. Known products advantageously usable in the context of thepresent invention include those available under the Novodur(manufacturer: Styrolution) and Magnum (manufacturer: Styron) brandnames. Particular preference is given to Novodur N H604.

The polymer is an essential part of the inventive coating compositionand of the inventive coating. The proportion of the at least one ABScopolymer in the solids content of the coating composition is at least30% by weight, preferably at least 40% by weight, more preferably atleast 45% by weight.

Reactive diluents usable with preference as component (b) of theinventive coating composition are bifunctional, trifunctional,tetrafunctional, pentafunctional or hexafunctional acrylic and/ormethacrylic monomers. Preference is given to ester functions, especiallyacrylic ester functions. Suitable polyfunctional acrylic acid and/ormethacrylic esters derive from aliphatic polyhydroxyl compounds havingat least 2, preferably at least 3 and more preferably at least 4hydroxyl groups, and preferably 2 to 12 carbon atoms.

Examples of such aliphatic polyhydroxyl compounds are ethylene glycol,propylene glycol, butane-1,4-diol, hexane-1,6-diol, diethylene glycol,triethylene glycol, glycerol, trimethylolpropane, pentaerythritol,dipentaerythritol, tetramethylolethane and sorbitan. Examples of estersof said polyhydroxyl compounds, said esters being suitable withpreference in accordance with the invention as bi- to hexafunctionalacrylic and/or methacrylic monomers for the reactive diluent, are glycoldiacrylate and dimethacrylate, butanediol diacrylate or dimethacrylate,dimethylolpropane diacrylate or dimethacrylate, diethylene glycoldiacrylate or dimethacrylate, divinylbenzene, trimethylolpropanetriacrylate or trimethacrylate, glyceryl triacrylate or trimethacrylate,pentaerythrityl tetraacrylate or tetramethacrylate, dipentaerythritylpenta-/hexaacrylate (DPHA), butane-1,2,3,4-tetraol tetraacrylate ortetramethacrylate, tetramethylolethane tetraacrylate ortetramethacrylate, 2,2-dihydroxypropane-1,3-diol tetraacrylate ortetramethacrylate, diurethane dimethacrylate (UDMA), sorbitan tetra-,penta- or hexaacrylate or the corresponding methacrylates. It is alsopossible to use additionally mixtures of crosslinking monomers havingtwo to four or more ethylenically unsaturated, free-radicallypolymerizable groups.

Additionally in accordance with the invention, it is possible to use, asreactive diluents or as components b) of the inventive coatingcomposition, alkoxylated di-, tri-, tetra-, penta- and hexaacrylates or-methacrylates. Examples of alkoxylated diacrylates or -methacrylatesare alkoxylated, preferably ethoxylated, methanediol diacrylate,methanediol dimethacrylate, glyceryl diacrylate, glyceryldimethacrylate, neopentyl glycol diacrylate, neopentyl glycoldimethacrylate, 2-butyl-2-ethylpropane-1,3-diol diacrylate,2-butyl-2-ethylpropane-1,3-diol dimethacrylate, trimethylolpropanediacrylate or trimethylolpropane dimethacrylate.

Examples of alkoxylated triacrylates or -methacrylates are alkoxylated,preferably ethoxylated, pentaerythrityl triacrylate, pentaerythrityltrimethacrylate, glyceryl triacrylate, glyceryl trimethacrylate,butane-1,2,4-triol triacrylate, butane-1,2,4-triol trimethacrylate,trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,tricyclodecanedimethanol diacrylate, tricyclodecanedimethanoldimethacrylate, ditrimethylolpropane tetraacrylate orditrimethylolpropane tetramethacrylate.

Examples of alkoxylated tetra-, penta- or hexaacrylates are alkoxylated,preferably ethoxylated, pentaerythrityl tetraacrylate, dipentaerythrityltetraacrylate, dipentaerythrityl pentaacrylate, dipentaerythritylhexaacrylate, pentaerythrityl tetramethacrylate, dipentaerythrityltetramethacrylate, dipentaerythrityl pentamethacrylate ordipentaerythrityl hexamethacrylate.

In the alkoxylated diacrylates or -methacrylates, triacrylates or-methacrylates, tetraacrylates or -methacrylates, pentaacrylates or-methacrylates and/or alkoxylated hexaacrylates or -methacrylates incomponent b), all the acrylate groups or methacrylate groups or onlysome of the acrylate groups or methacrylate groups in the respectivemonomer may be bonded to the corresponding radical via alkylene oxidegroups. It is also possible to use any desired mixtures of such whollyor partly alkoxylated di-, tri-, tetra-, penta- or hexaacrylates or-methacrylates. In this case, it is also possible that the acrylate ormethacrylate group(s) is/are bonded to the aliphatic, cycloaliphatic oraromatic radical of the monomer via a plurality of successive alkyleneoxide groups, preferably ethylene oxide groups. The mean number ofalkylene oxide or ethylene oxide groups in the monomer is stated by thealkoxylation level or ethoxylation level. The alkoxylation level orethoxylation level may preferably be from 2 to 25, particular preferencebeing given to alkoxylation levels or ethoxylation levels of 2 to 15,most preferably of 3 to 9.

Likewise in accordance with the invention, reactive diluents orcomponents b) of the inventive coating composition may be oligomerswhich belong to the class of the aliphatic urethane acrylates or of thepolyester acrylates or polyacryloylacrylates. The use thereof as paintbinders is known and is described in Chemistry & Technology of UV & EBFormulation for Coatings, Inks & Paints, vol. 2, 1991, SITA Technology.London (P. K. T. Oldring (ed.) on p. 73-123 (Urethane Acrylates) and p.123-135 (Polyester Acrylates). Commercially available examples which aresuitable within the inventive context include aliphatic urethaneacrylates such as Ebecryl® 4858, Ebecryl® 284, Ebecryl® 265, Ebecryl®264, Ebecryl® 8465, Ebecryl® 8402 (each manufactured by Cytec SurfaceSpecialities), Craynor® 925 from Cray Valley, Viaktin® 6160 from VianovaResin, Desmolux VP LS 2265 from Bayer MaterialScience AG, Photomer 6891from Cognis, or else aliphatic urethane acrylates dissolved in reactivediluents, such as Laromer® 8987 (70% in hexanediol diacrylate) from BASFAG, Desmolux U 680 H (80% in hexanediol diacrylate) from BayerMaterialScience AG, Craynor® 945B85 (85% in hexanediol diacrylate),Ebecryl® 294/25HD (75% in hexanediol diacrylate), Ebecryl® 8405 (80% inhexanediol diacrylate), Ebecryl® 4820 (65% in hexanediol diacrylate)(each manufactured by Cytec Surface Specialities) and Craynor® 963B80(80% in hexanediol diacrylate), each from Cray Valley, or else polyesteracrylates such as Ebecryl® 810, 830, or polyacryloylacrylates such asEbecryl®, 740, 745, 767 or 1200 from Cytec Surface Specialities.

In a further preferred embodiment, the reactive diluent (b) comprisesalkoxylated diacrylates and/or dimethacrylates, alkoxylated triacrylatesand/or trimethacrylates, alkoxylated tetraacrylates and/ortetramethacrylates, alkoxylated pentaacrylates and/orpentamethacrylates, alkoxylated hexaacrylates and/or hexamethacrylates,aliphatic urethane acrylates, polyester acrylates, polyacryloylacrylatesand mixtures thereof.

In a further preferred embodiment, the reactive diluent (b) of theinventive coating composition comprises dipentaerythritylpenta-hexacrylate.

The invention also encompasses mixtures of the abovementionedcrosslinking multifunctional monomers with monofunctional monomers suchas, more particularly, methyl methacrylate. The proportion of themultifunctional monomers in such a mixture is preferably at least 20% byweight.

The reactive diluent is an essential part of the inventive coatingcomposition and of the inventive coating. The total proportion of the atleast one reactive diluent in the solids content of the coatingcomposition is at least 30% by weight, preferably at least 40% byweight, more preferably at least 45% by weight.

The content of ethylenically unsaturated groups has a significantinfluence on the achievable durability properties of the radiation-curedcoating. Therefore, the inventive coating composition contains a contentof ethylenically unsaturated groups of at least 3.0 mol per kg of solidscontent of the coating composition, preferably at least 3.5 mol per kg,more preferably at least 4.0 mol per kg of solids content of the coatingcomposition. This content of ethylenically unsaturated groups is alsowell known to the person skilled in the art by the term “double bonddensity”.

The term “at least one photoinitiator” in the inventive coatingcomposition encompasses the standard, commercially available compoundsknown to those skilled in the art, for example α-hydroxyketones,benzophenone, α,α-diethoxyacetophenone, 4,4-diethylaminobenzophenone,2,2-dimethoxy-2-phenylacetophenone, 4-isopropylphenyl 2-hydroxy-2-propylketone, 1-hydroxycyclohexyl phenyl ketone, isoamylp-dimethylaminobenzoate, methyl 4-dimethylaminobenzoate, methylo-benzoylbenzoate, benzoin, benzoin ethyl ether, benzoin isopropylether, benzoin isobutyl ether, 2-hydroxy-2-methyl-1-phenylpropan-1-one,2-isopropylthioxanthone, dibenzosuberone,2,4,6-trimethylbenzoyldiphenylphosphine oxide, bisacylphosphine oxideand others, said photoinitiators being utilizable alone or in acombination of two or more or in combination with one of the abovepolymerization initiators.

UV photoinitiators used may, for example, be IRGACURE® products fromBASF, for example the products IRGACURE® 184, IRGACURE® 500, IRGACURE®1173, IRGACURE® 2959, IRGACURE® 745, IRGACURE® 651, IRGACURE® 369,IRGACURE® 907, IRGACURE® 1000, IRGACURE® 1300, IRGACURE® 819, IRGACURE®819DW, IRGACURE® 2022, IRGACURE® 2100, IRGACURE® 784, IRGACURE® 250; inaddition, the DAROCUR® products from BASF may be used, for example theproducts DAROCUR® MBF, DAROCUR® 1173, DAROCUR® TPO, DAROCUR® 4265.Another example of a UV photoinitiator usable in the inventive coatingcomposition can be purchased under the Esacure One trade name from themanufacturer Lamberti.

Photoinitiators are present in the coating composition in the range from≥0.1 to ≤10 parts by weight of the solids content of the coatingcomposition.

The coating composition should additionally contain, over and above the100 parts by weight of components (a), (b) and (c), one or more organicsolvents.

Suitable solvents are particularly those that do not attackpolycarbonate polymers. Such solvents are preferably alcohols. In apreferred embodiment of the present invention, the solvent (d) isselected from 1-methoxy-2-propanol, diacetone alcohol,2,2,3,3-tetrafluoropropanol and mixtures thereof. Most preferably, theat least one solvent (d) comprises a mixture of 1-methoxy-2-propanol andat least 50% by weight of diacetone alcohol.

The coating material composition thus preferably contains, in additionto the 100 parts by weight of components (a) to (c), 0 to 900 parts byweight, more preferably 100 to 850 parts by weight, most preferably 200to 800 parts by weight, of the at least one organic solvent.

The coating composition may additionally optionally contain, over andabove the 100 parts by weight of components (a), (b) and (c), one ormore further coatings additives. Such coatings additives may beselected, for example, from the group comprising stabilizers, levellingagents, surface additives, pigments, dyes, inorganic nanoparticles,adhesion promoters, UV absorbers, IR absorbers, preferably from thegroup comprising stabilizers, levelling agents, surface additives andinorganic nanoparticles. The coating composition may preferably contain,in addition to the 100 parts by weight of components 1) to 3), 0 to 40parts by weight, more preferably 0 to 30 parts by weight, mostpreferably 0.1 to 20 parts by weight, of at least one further coatingsadditive. Preferably, the total proportion of all the coatings additivespresent in the coating material composition is 0 to 40 parts by weight,more preferably 0 to 30 parts by weight, most preferably 0.1 to 20 partsby weight.

The coating material composition may comprise inorganic nanoparticles toincrease the mechanical durability, for example scratch resistanceand/or pencil hardness.

Useful nanoparticles include inorganic oxides, mixed oxides, hydroxides,sulphates, carbonates, carbides, borides and nitrides of elements ofmain group II to IV and/or elements of transition group I to VIII of thePeriodic Table, including the lanthanides. Preferred nanoparticles aresilicon oxide, aluminium oxide, cerium oxide, zirconium oxide, niobiumoxide, zinc oxide or titanium oxide nanoparticles, particular preferencebeing given to silicon oxide nanoparticles.

The particles used preferably have mean particle sizes (measured bymeans of dynamic light scattering in dispersion, determined as theZ-average) of less than 200 nm, preferably of 5 to 100 nm, morepreferably 5 to 50 nm. Preferably at least 75%, more preferably at least90%, even more preferably at least 95%, of all the nanoparticles usedhave the sizes defined above.

The coating composition can be produced in a simple manner by first ofall completely dissolving or colloidally dispersing the polymer in thesolvent at room temperature or at elevated temperatures and then theother obligatory and any optional components to the solution which hasbeen cooled down to room temperature, either combining them in theabsence of solvent(s) and mixing them together by stirring, or in thepresence of solvent(s), for example adding them to the solvent(s), andmixing them together by stirring. Preferably, first the photoinitiatoris dissolved in the solvent(s) and then the further components areadded. This is optionally followed by a purification by means offiltration, preferably by means of fine filtration.

The present invention further provides a laminate comprising a substrateand a surface coating obtainable by coating the substrate with thecoating composition according to the present invention. This provides,in accordance with the invention, a coated substrate having advantageoussurface properties in terms of scratch resistance, solvent resistanceand metallizable surface.

Since the metallization of surfaces in the field of production ofplastics parts by means of the film insert moulding process is ofparticular significance, and since the present invention advantageouslyachieves an improvement, the substrate to be coated, according to thepresent invention, preferably comprises a film.

Therefore, the present invention further provides a coated filmcomprising a film of a thermoplastic polymer and a coating obtainable bycoating with the inventive coating composition.

Films used for coating are preferably thermoplastics such aspolycarbonate, polyacrylate or poly(meth)acrylate, polysulphones,polyesters, thermoplastic polyurethane and polystyrene, and thecopolymers and mixtures (blends) thereof. Suitable thermoplastics are,for example, polyacrylates, poly(meth)acrylates (e.g. PMMA; e.g.Plexiglas® from the manufacturer Röhm), cycloolefin copolymers (COC;e.g. Topas® from the manufacturer Ticona; Zenoex® from the manufacturerNippon Zeon or Apel® from the manufacturer Japan Synthetic Rubber),polysulphones (Ultrason@ from the manufacturer BASF or Ude® from themanufacturer Solvay), polyesters, for example PET or PEN, polycarbonate(PC), polycarbonate/polyester blends, e.g. PC/PET,polycarbonate/polycyclohexylmethanol cyclohexanedicarboxylate (PCCD;Xylecs® from GE), polycarbonate/PBT and mixtures thereof.

In a particularly advantageous and preferred embodiment of the presentinvention, the film of the inventive laminate or the thermoplasticpolymer of the film coated in accordance with the invention comprisespolycarbonate or copolycarbonate.

Suitable polycarbonates for the production of the inventivepolycarbonate compositions are all the known polycarbonates. These arehomopolycarbonates, copolycarbonates and thermoplastic polyestercarbonates. The suitable polycarbonates preferably have mean molecularweights M _(w) of 18 000 to 40 000, preferably of 26 000 to 36 000 andespecially of 28 000 to 35 000, determined by measuring the relativesolution viscosity in dichloromethane or in mixtures of equal weights ofphenol/o-dichlorobenzene, calibrated by light scattering.

The polycarbonates are preferably prepared by the interfacial process orthe melt transesterification process, which have been described manytimes in the literature. With regard to the interfacial process,reference is made by way of example to H. Schnell, Chemistry and Physicsof Polycarbonates, Polymer Reviews, vol. 9, Interscience Publishers, NewYork 1964 p. 33 ff., to Polymer Reviews, vol. 10, “Condensation Polymersby Interfacial and Solution Methods”, Paul W. Morgan, IntersciencePublishers, New York 1965, ch. VIII, p. 325, to Drs. U. Grigo, K.Kircher and P. R. Müller “Polycarbonate” [Polycarbonates] inBecker/Braun, Kunststoff-Handbuch [Polymer Handbook], volume 3/1,Polycarbonate, Polyacetale, Polyester, Celluloseester [Polycarbonates,Polyacetals, Polyesters, Cellulose Esters], Carl Hanser Publishers,Munich, Vienna, 1992, p. 118-145, and to EP 0 517 044 A1. The melttransesterification process is described, for example, in theEncyclopedia of Polymer Science, vol. 10 (1969), Chemistry and Physicsof Polycarbonates, Polymer Reviews, H. Schnell, vol. 9, John Wiley andSons, Inc. (1964), and in patent specifications DE-B 10 31 512 and U.S.Pat. No. 6,228,973.

The polycarbonates can be obtained from reactions of bisphenol compoundswith carbonic acid compounds, especially phosgene, or diphenyl carbonateor dimethyl carbonate in the melt transesterification process.Particular preference is given here to homopolycarbonates based onbisphenol A and copolycarbonates based on monomers bisphenol A and1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane. Further bisphenolcompounds which can be used for the polycarbonate synthesis aredisclosed, inter alia, in WO 2008/037364 A1, EP 1 582 549 A1, WO2002/026862 A1 and WO 2005/113639 A1.

The polycarbonates may be linear or branched. It is also possible to usemixtures of branched and unbranched polycarbonates.

Suitable branching agents for polycarbonates are known from theliterature and are described, for example, in patent specifications U.S.Pat. No. 4,185,009 B1, DE 25 00 092 A1, DE 42 40 313 A1, DE 19 943 642A1, U.S. Pat. No. 5,367,044 B1, and in literature cited therein.Furthermore, the polycarbonates used may also be intrinsically branched,in which case no branching agent is added in the course of polycarbonatepreparation. One example of intrinsic branches is that of so-calledFries structures, as disclosed for melt polycarbonates in EP 1 506 249A1.

In addition, it is possible to use chain terminators in thepolycarbonate preparation. The chain terminators used are preferablyphenols such as phenol, alkylphenols such as cresol and4-tert-butylphenol, chlorophenol, bromophenol, cumylphenol or mixturesthereof.

The polymer composition(s) of the film or of the thermoplastic polymerof the 3D moulding may additionally comprise additives, for example UVabsorbers, IR absorbers and other customary processing aids, especiallydemoulding agents and fluxes, and also the customary stabilizers,especially thermal stabilizers, and also antistats, pigments, colourantsand optical brighteners. In every layer, different additives orconcentrations of additives may be present.

Coatings obtainable by coating with the inventive coating composition,i.e. the coated films of the invention, are particularly advantageouslysuitable for coating with a metal layer. In a further preferredembodiment, the coated film of the invention therefore comprises a metallayer on the coated surface. The metal layer preferably comprises atleast one metal selected from the group consisting of tin, lead, silver,gold, palladium, platinum, cobalt, manganese, bismuth, copper, nickel,iron, chromium and mixtures thereof, preferably nickel, silver, gold,palladium, platinum, copper and chromium, more preferably nickel, gold,palladium, copper and chromium.

The present invention further provides a process for producing a coatedfilm, comprising the steps of

-   -   (i) coating a film with a coating composition according to the        present invention;    -   (ii) drying the coating;    -   (iii) optionally cutting the film to size and/or delaminating,        printing and/or thermally or mechanically forming the film; and    -   (iv) irradiating the coating with UV radiation to cure the        coating.

The film can be coated with the coating composition by the standardmethods for coating films with fluid coating compositions, for exampleby knife-coating, spraying, pouring, flow-coating, dipping, rolling orspin-coating. The flow-coating process can be effected manually with ahose or suitable coating head, or automatically in a continuous run bymeans of flow-coating robots and optionally slot dies. Preference isgiven to the application of the coating composition by a roll-to-rolltransfer. In this case, the surface of the film to be coated may bepretreated by cleaning or activation.

The drying follows the application of the coating composition to thefilm. For this purpose, more particularly, elevated temperatures inovens, and moving and optionally also dried air, for example inconvection ovens or by means of nozzle dryers, and thermal radiationsuch as IR and/or NIR, are employed. In addition, it is possible to usemicrowaves. It is possible and advantageous to combine a plurality ofthese drying processes. The drying of the coating in step (ii)preferably comprises flash-off at room temperature and/or elevatedtemperature, such as preferably at 20-200° C., more preferably at40-120° C. After the coating has been dried, it is blocking-resistant,and so the coated substrate, especially the coated film, can belaminated, printed and/or thermally formed. Forming in particular ispreferred in this context, since merely the forming of a coated filmhere can define the mould for a film insert moulding process forproduction of a three-dimensional plastics part.

Advantageously, the conditions for the drying are selected such that theelevated temperature and/or the thermal radiation does not trigger anypolymerization (crosslinking) of the acrylate or methacrylate groups,since this can impair formability. In addition, the maximum temperatureattained should appropriately be selected at a sufficiently low levelthat the film does not deform in an uncontrolled manner.

After the drying/curing step, the coated film, optionally afterlamination with a protective film on the coating, can be rolled up. Thefilm can be rolled up without the coating sticking to the reverse sideof the substrate film or of the laminating film. However, it is alsopossible to cut the coated film to size and to send the cut sectionsindividually or as a stack to further processing. Particular preferenceis given in this context to the thermal forming of the coated film to athree-dimensional mould, as undertaken as a preparatory step for insertmoulding of the film with a thermoplastic polymer such as polycarbonatein a film insert moulding process. In a preferred embodiment, step (iii)comprises the cutting-to-size and thermal forming of the coated film.

Curing with actinic radiation is understood to mean the free-radicalpolymerization of ethylenically unsaturated carbon-carbon double bondsby means of initiator radicals which are released, for example, from theabove-described photoinitiators through irradiation with actinicradiation.

The radiative curing is preferably effected by the action of high-energyradiation, i.e. UV radiation or daylight, for example light ofwavelength ≥200 nm to ≤750 nm, or by irradiation with high-energyelectrons (electron beams, for example ≥90 keV to ≤300 keV). Theradiation sources used for light or UV light are, for example, moderate-or high-pressure mercury vapour lamps, wherein the mercury vapour may bemodified by doping with other elements such as gallium or iron. Lasers,pulsed lamps (known by the name UV flashlight emitters), halogen lampsor excimer emitters are likewise usable. The emitters may be installedat a fixed location, such that the material to be irradiated is movedpast the radiation source by means of a mechanical device, or theemitters may be mobile, and the material to be irradiated does notchange position in the course of curing. The radiation dose typicallysufficient for crosslinking in the case of UV curing is in the rangefrom ≥80 mJ/cm² to ≤5000 mJ/cm².

In a preferred embodiment, the actinic radiation is therefore light inthe UV light range.

The radiation can optionally be performed with exclusion of oxygen, forexample under inert gas atmosphere or reduced-oxygen atmosphere.Suitable inert gases are preferably nitrogen, carbon dioxide, noblegases or combustion gases. In addition, the radiation can be effected bycovering the coating with media transparent to the radiation. Examplesthereof are polymer films, glass or liquids such as water.

According to the radiation dose and curing conditions, the type andconcentration of any initiator used can be varied or optimized in amanner known to those skilled in the art or by exploratory preliminarytests. For curing of the formed films, it is particularly advantageousto conduct the curing with several emitters, the arrangement of whichshould be selected such that every point on the coating receivessubstantially the optimal radiation dose and intensity for curing. Moreparticularly, unirradiated regions (shadow zones) should be avoided.

In addition, according to the film used, it may be advantageous toselect the irradiation conditions such that the thermal stress on thefilm does not become too great. In particular, thin films and films madefrom materials having a low glass transition temperature can have atendency to uncontrolled deformation when a particular temperature isexceeded as a result of the irradiation. In these cases, it isadvantageous to allow a minimum level of infrared radiation to act onthe substrate, by means of suitable filters or a suitable design of theemitters. In addition, reduction of the corresponding radiation dose cancounteract uncontrolled deformation. However, it should be noted that aparticular dose and intensity in the irradiation are needed for maximumpolymerization. It is particularly advantageous in these cases toconduct curing under inert or reduced-oxygen conditions, since therequired dose for curing decreases when the oxygen content is reduced inthe atmosphere above the coating.

Particular preference is given to using mercury emitters in fixedinstallations for curing. In that case, photoinitiators are used inconcentrations of ≥0.1% by weight to ≤10% by weight, more preferably of≥0.2% by weight to ≤3.0% by weight, based on the solids content of thecoating. These coatings are preferably cured using a dose of ≥80 mJ/cm²to ≤5000 mJ/cm².

Optional insert moulding of the coated film with a thermoplasticpolymer, such as polycarbonate, in a step (v) on completion of curing ofthe film coating and the optional, usually desirable, forming of thecoated film is well known to the person skilled in the art in the formof the film insert moulding process as described, for example, in WO2004/082926 A1 and WO 02/07947 A1. In a preferred embodiment of theprocess according to the invention, the reverse coating of the film in astep (v) is effected by means of extrusion or injection moulding,preferably with polycarbonate melt. The processes of extrusion and ofinjection moulding for this purpose are well known to those skilled inthe art and are described, for example, in “Handbuch Spritzgießen”[Injection Moulding Handbook], Friedrich Johannnnaber/Walter Michaeli,Munich; Vienna: Hanser, 2001, ISBN 3-446-15632-1 or “Anleitung zum Bauvon Spritzgießwerkzeugen” [Introduction to the Construction of InjectionMoulds], Menges/Michaeli/Mohren, Munich; Vienna: Hanser, 1999, ISBN3-446-21258-2.

After curing by irradiation with UV light, the coated surface of thecoated polycarbonate film produced in this way then has the inventivecombination of properties in terms of scratch resistance, solventresistance and metallizability. In this way, it is likewise possible bymeans of the inventive insert moulding of the coated film with athermoplastic polymer, as is customary in film insert mouldingprocesses, to produce mouldings having surfaces consisting of theinventive coating of the inventive film and having desired propertiessuch as scratch resistance, solvent resistance and metallizability.

The inventive coating can be metallized by known processes for plasticsgalvanization from the prior art. In a further preferred embodiment, theprocess of the invention therefore comprises a further step (vi) ofcoating the surface with a metallic coating.

In these processes, one option is to first etch the polymer surface inorder to roughen or chemically alter it. This can be done, for example,by means of mineral acids, chromic acid, sulphuric acid or acidic oralkaline permanganate solutions. Further pretreatment methods known fromthe prior art include a plasma treatment or treatment with oxidizingetchants.

For example, the etching operation roughens or chemically alters thepolymer surface such that adhesion between plastic and metal coating isenabled. The etched plastics parts are rinsed and then activated. In theprior art, different methods for activation of the polymer surfaces areknown. For example, a known method is to activate the polymer surfaceswith noble metals, for example colloidal palladium, ionogenic palladiumor silver colloids. A further known method is to use metals which formsparingly soluble sulphides or polysulphides as activators for thedirect metallization. In this context, tin, lead, silver, bismuth,cobalt, manganese and copper in particular have been found to besuitable.

The activation may be followed either by an electroless metallization ofthe surface to form a conductive layer, followed by a subsequentelectrolytic layer formation, or by a direct chemical metal deposition.In the case of use of palladium activation, this metal deposition istypically effected from an acidic copper bath, whereas, in the case ofuse of sulphide or polysulphide activators, metal is deposited from anickel bath, as described, for example, in DE 102004026489 B3. Inaddition, step (vi) may preferably encompass those process stepsdescribed in WO 2012/120007 A1 at page 19 line 9 to page 20 line 4. Thistext passage of WO 2012/120007 A1 and the corresponding description arehereby explicitly incorporated by reference.

In a preferred embodiment, the process of the invention comprises steps(i), (ii), (iii), (iv) and (v). In this way, a 3D moulding is obtained,the surface of which is scratch-resistant and solvent-resistant, andwhich is advantageously metallizable. Therefore, in a furtheradvantageous configuration of this embodiment, the process includes thefurther step (vi). In this way, a 3D moulding made from plastic with ametallic surface is provided. In a further preferred embodiment, theprocess of the invention comprises steps (i), (ii), (iii), (iv) and(vi). In this way, a formed polymer film, preferably a polycarbonatefilm, provided with a metallic coating is provided.

On account of the advantageous combination of properties of scratchresistance, solvent resistance and metallizability of the surfaces ofthe coated films of the invention, these films are particularly suitablefor production of 3D plastics parts, especially those which are obtainedby film insert moulding processes. The surfaces of the plastics partsthus have the particular properties of the inventive films. The presentinvention therefore further provides a 3D plastics part comprising thecoated film of the invention, especially the coated polycarbonate film,preferably with a metal layer on the coated film. In a particularlypreferred embodiment, the 3D plastics part according to the presentinvention is obtainable by a film insert moulding process. Processes ofthis kind include the insert moulding, for example by injectionmoulding, of the inventive coated polycarbonate films with athermoplastic polymer, especially with polycarbonate.

Therefore, the present invention further provides for the use of thecoated film of the invention, especially of the coated polycarbonatefilm of the invention, for production of plastics parts in film insertmoulding processes. In a particularly preferred embodiment, theinventive use comprises the production of plastics parts for theautomotive, transport, electricals, electronics and constructionindustries in film insert moulding processes.

The present invention thus further provides a moulded componentcomprising at least one coated film according to the present invention,especially a moulded component where the coating of the coated filmcomprises at least one metal layer on the surface.

EXAMPLES

Assessment Methods

Layer Thickness

The layer thickness of the coatings was measured by observing thecutting edge in an Axioplan optical microscope manufactured by Zeiss.Method—reflected light, bright field, magnification 500×.

Assessment of Blocking Resistance

Conventional test methods as described, for instance, in DIN 53150 areinsufficient to simulate the blocking resistance of rolled-up,pre-dried, coated films, and therefore the following test was employed:The coating materials were applied to Makrofol DE 1-1 (375 μm) with aconventional coating bar (target wet film thickness 100 μm). After aflash-off phase at 20° C. to 25° C. for 10 min, the coated films weredried in an air circulation oven at 110° C. for 10 min. After a coolingphase for 1 min, a commercial GH-X173 natur pressure-sensitivelamination film (manufacturer: Bischof und Klein, Lengerich, Germany)was applied without creasing to the dried coated film with a plasticroller over an area of 100 mm×100 mm. Subsequently, the laminated filmpiece was subjected to a weight of 10 kg over the full area for 1 hour.Thereafter, the lamination film was removed and the coated surface wasassessed visually.

Assessment of Pencil Hardness

The pencil hardness was measured analogously to ASTM D 3363 using anElcometer 3086 Scratch boy (Elcometer Instruments GmbH, Aalen, Germany)under a load of 500 g, unless stated otherwise.

Assessment of Steel Wool Scratching

The steel wool scratching was determined by sticking a piece of No. 00steel wool (Oskar Weil GmbH Rakso, Lahr, Germany) onto the flat end of a500 g fitter's hammer, the area of the hammer being 2.5 cm×2.5 cm, i.e.approximately 6.25 cm². The hammer was placed onto the surface to betested without applying additional pressure, such that a defined load ofabout 560 g was attained. The hammer was then moved back and forth 10times in twin strokes. Subsequently, the stressed surface was cleanedwith a soft cloth to remove fabric residues and coating particles. Thescratching was characterized by haze and gloss values, measuredtransverse to the scratching direction, with a Micro HAZE plus (20°gloss and haze; Byk-Gardner GmbH, Geretsried, Germany). The measurementwas effected before and after scratching. The differential values forgloss and haze before and after stress are reported as Δgloss and Δhaze.

Assessment of Solvent Resistance

The solvent resistance of the coatings was typically tested withisopropanol, xylene, 1-methoxy-2-propyl acetate, ethyl acetate, acetone,in technical-grade quality. The solvents were applied to the coatingwith a cotton bud soaked therewith and protected from vaporization bycovering. Unless stated otherwise, a contact time of 60 minutes at about23° C. was observed. After the end of the contact time, the cotton budwas removed and the test surface was wiped clean with a soft cloth. Theinspection was immediately effected visually and after gentle scratchingwith a fingernail.

A distinction is made between the following levels:

-   -   0=unchanged; no change visible; cannot be damaged by scratching.    -   1=slight swelling visible, but cannot be damaged by scratching.    -   2=change clearly visible, can barely be damaged by scratching.    -   3=noticeable change, surface destroyed after firm fingernail        pressure.    -   4=significant change, scratched through to the substrate after        firm fingernail pressure.    -   5=destroyed; the coating is already destroyed when the chemical        is wiped away; the test substance cannot be removed (has eaten        into the surface).

Within this assessment, the test is typically passed with the ratings of0 and 1. Ratings of >1 represent a “fail”.

Example 1: Production of a Coating Composition

117 g of Novodur® N H604 (manufacturer: Styrolution) were distributedhomogeneously in 284 g of a mixture (2:3) of 1-methoxy-2-propanol anddiacetone alcohol at 100° C. within about 3 h. The stable colloidalsolution obtained in this way was cooled down to about 30° C.Separately, the following components were dissolved in 166 g of themixture (2:3) of 1-methoxy-2-propanol and diacetone alcohol at roomtemperature: 117 g of dipentaerythrityl penta-/hexaacrylate (DPHA,manufacturer: Cytec), 4.7 g of Esacure One (manufacturer: Lamberti),2.35 g of Darocur 4265 (manufacturer: BASF) and 0.25 g of BYK 333(manufacturer: BYK). The second solution was added to the polymersolution while stirring. The coating composition obtained was stirred atroom temperature and with shielding from direct incidence of light foranother 3 h, dispensed and left to stand for 1 day. The yield was 665 g,the viscosity (23° C., DIN EN ISO 3219) was 1050 mPas, the solidscontent was 35% by weight and the calculated double bond density in thesolids content of the coating material was about 5.1 mol/kg.

Example 2: Testing of the Solubility of Various ABS Products

For the testing, various commercially available ABS products were used.The solubility was tested in a mixture (2:3) of 1-methoxy-2-propanol(MP-ol) and diacetone alcohol (DAA). For the testing, the aim was ause-relevant concentration of 20% by weight of the polymer in eachsolvent. The dissolution test was conducted at 120° C. while stirringfor 4 h. Then an intermediate result was registered. The solution wasthen allowed to cool to room temperature and the final result wasregistered.

Composition, % by wt. Acrylo- Poly- MP-ol/DAA = 2:3 nitrile Styrenebutadiene 120° C. 20° C. Novodur N 40^(#) 43^(#) 17^(#) two phases twophases H950 Novodur N 23^(#) 61^(#) 16^(#) homogeneous cloudyhomogeneous H604 blend cloudy blend Magnum 3404 24^(#) 66^(#) 10^(#)homogeneous cloudy homogeneous blend cloudy blend Magnum 3904 23^(#)62^(#) 15^(#) homogeneous cloudy homogeneous blend cloudy blend Magnum3616 24^(#) 62^(#) 14^(#) homogeneous cloudy homogeneous blend cloudyblend Magnum 8391 24^(#) 65^(#) 11^(#) homogeneous cloudy homogeneousblend cloudy blend Magnum 8434 22^(#) 67^(#) 11^(#) homogeneous cloudyhomogeneous blend cloudy blend ^(#)determination by IR spectroscopy;Novodur ® is a brand name of the manufacturer Styrolution; Magnum ® is abrand name of the manufacturer Styron.

In this way, it was possible to show that styrene-based ABS copolymershaving an acrylonitrile content of less than 30% by weight haveparticularly good solubility in solvent mixtures of 1-methoxy-2-propanoland diacetone alcohol preferred in accordance with the presentinvention. Thus, ABS copolymers having an acrylonitrile content in therange of ≥20% by weight to ≤30% by weight, especially in the range of≥22% by weight to ≤25% by weight, and especially in combination with aproportion of the polybutadiene in the range of ≥10% by weight to ≤16%by weight, are particularly preferred in the context of the presentinvention, especially in combination with a solvent mixture of1-methoxy-2-propanol and diacetone alcohol.

Example 3: Coating of Films

Coating compositions according to Example 1 were applied to a backingfilm, for example Makrofol DE 1-1 (Bayer MaterialScience AG, Leverkusen,Germany), by means of a slot coater from the manufacturer TSE TrollerAG. The layer thickness of the backing film was 250 μm.

Typical application conditions here were as follows:

-   -   web speed 1.3 to 2.0 m/min    -   wet coating material applied 20-150 μm    -   air circulation dryer 90-110° C., preferably in the region of        the TG of the polymer to be dried.    -   residence time in the dryer 3.5-5 min.

The coating was effected roll to roll, meaning that the polycarbonatefilm was unrolled in the coating system. The film was conducted throughone of the abovementioned application units and contacted with thecoating solution. Thereafter, the film with the wet coating was runthrough the dryer. After leaving the dryer, the now dry coating wastypically provided with a lamination film, in order to protect it fromsoiling and scratching. Thereafter, the film was rolled up again.

For the testing of the final properties of the product, the coated film,after leaving the dryer, can first be cured with a UV lamp and thenprovided with a lamination film.

Example 4: Testing of Blocking Resistance

The coated sides of the non-UV-cured films produced in Example 3 werecovered with a lamination film of the GH-X 173 A type (Bischof+Klein,Lengerich, Germany) and weighted down with an aluminium sheet ofdimensions 4.5×4.5 cm² and a weight of 2 kg at about 23° C. for 1 h.Thereafter, the weight and the lamination film were removed and thesurface of the coating—was checked visually for changes.

TABLE 1 Blocking resistance of the coatings Coating Layer thickness onBlocking composition 250 μm PC film resistance Example 1  8 μm OKExample 1 13 μm OK Example 1 18 μm OK Example 1 24 μm OK

Example 5: Forming of the Coated Films and Curing of the Coatings

The HPF forming tests were performed on an SAMK 360 system. The mouldwas electrically heated to 100° C. The film heating was undertaken bymeans of IR emitters at 240, 260 and 280° C. The heating time was 16seconds. A film temperature of about 170° C. was attained. The formingwas effected at a forming pressure of 100 bar. The forming mould was aheating/ventilation panel (HV panel).

The appropriate film sheet was fixed at an exact position on a pallet.The pallet passed through the forming station into the heating zone andresided therein for the time set (16 s). In the course of this, the filmwas heated in such a way that the film briefly experienced a temperatureabove the softening point; the core of the film was about 10-20° C.colder. As a result, the film was relatively stable when it is run intothe forming station.

In the forming station, the film was fixed by closing the mould over theactual mould; at the same time, the film was formed over the mould bymeans of gas pressure. The pressure hold time of 7 s ensured that thefilm was accurately formed by the mould. After the hold time, the gaspressure was released again. The mould opened and the formed film wasrun out of the forming station.

The film was subsequently removed from the pallet and could then becured with UV light.

With the mould used, radii down to 1 mm were formed.

The UV curing of the inventive coating was executed with an evo 7 drhigh-pressure mercury vapour lamp (ssr engineering GmbH, Lippstadt,Germany). This system is equipped with dichroitic reflectors and quartzdiscs, and has a specific power of 160 W/cm. A UV dose of 2.0 J/cm² andan intensity of 1.4 W/cm² were applied. The surface temperature was toreach >60° C.

The UV dose figures were determined with a Lightbug ILT 490(International Light Technologies Inc., Peabody Mass., USA). The surfacetemperature figures were determined with temperature test strips of theRS brand (catalogue number 285-936; RS Components GmbH, Bad Hersfeld,Germany).

Results for the durability of the coatings which have been crosslinkedusing the conditions specified can be found in Table 2.

TABLE 2 Chemical resistance and scratch resistance of the coatingsCoating Steel wool composition/ Pencil (manufacturer: Layer Solventhardness Rakso, No. 00) thickness on IP/MPA/X/EA/Ac 500 g 560 g/10 DH250 μm PC film 1 h/RT Mitsubishi ΔG/ΔH Haze Example 1/8 μm 0/0/0/0/0 HB6/0 1.36 Example 1/13 μm 0/0/0/0/0 HB  7/18 2.82 Example 1/18 μm0/0/0/0/0 F-H 12/24 4.27 Example 1/24 μm 0/0/0/0/0 F-H 10/5  7.66Makrofol DE 1-1 0/5/5/5/5 3B 100/285 — 250 μm

IP/MPA/X/EA/Ac stands for isopropanol, 1-methoxy-2-propyl acetate,xylene, ethyl acetate, acetone

RT stands for room temperature, about 23° C. here. Makrofol DE 1-1, 250μm is an uncoated polycarbonate film (manufacturer: BayerMaterialScience).

As Table 2 shows, the inventive coating, even in a thin layer,distinctly improves the pencil hardness and scratch resistance of thefilm compared to the known properties of the polycarbonate. The coatingalso imparts a high solvent resistance. Compared to extruded ABS layers,the optical cloudiness (haze) of the ABS layer can be significantlyreduced by appropriately thin coating, without losing themetallizability.

Example 6: Metallization (Galvanization)

The roughening of the surface of the ABS polymer was effected in achromosulphuric acid etchant at a working temperature of 60° C. Thedipping time was 10 minutes. It is assumed that, during this operation,a constituent of the ABS, the butadiene rubber, was leached out of thesurface under oxidation, and that caverns in the microscopic range wereformed in this way. Thereafter, the parts were rinsed vigourously withwater and with sodium hydrogensulphite solution.

Palladium nuclei were inserted into the cavities formed by the processesdescribed in DE 10 2004 026 489 B3 as an activator, which catalysed thesubsequent chemical nickel-plating in the nickel bath (nickel sulphate;ammonia and sodium hypophosphite), as described in WO 2012/120007 A1,page 19 line 30 to page 20 line 4. Thus, a first thin, conductive nickellayer was obtained, which had very good mechanical interlocking with theplastic through the filling of the cavities, and had correspondinglygood adhesion.

It was then possible to deposit further metal layers on this conductivelayer by electrochemical means.

Formed films produced in the HPF process having the inventive coating,UV-cured and insert-moulded with thermoplastic, show a homogeneous,conductive nickel layer after the above treatment.

As the examples clearly showed, the coated films of the invention havescratch-resistant and solvent-resistant surfaces. In addition, thesesurfaces have good metallizability in the standard processes. Thus, theinventive coating composition and the inventive films are of excellentsuitability for production of all kinds of mouldings with metallicsurfaces, especially by film insert moulding processes.

The invention claimed is:
 1. A coated film comprising a film of athermoplastic polymer, a coating obtained by coating with a coatingcomposition having a solids content and a content of ethylenicallyunsaturated groups comprising (a) at least one then thermoplasticacrylonitrile-butadiene-styrene copolymer in a content of at least 30%by weight of the solids content of the coating composition, wherein theacrylonitrile-butadiene-styrene copolymer has an acrylonitrile contentin the range from ≥19% to ≤35%; (b) at least one UV-curable reactivediluent in a content of at least 30% by weight of the solids content ofthe coating composition; (c) at least one photoinitiator in a content of≥0.1 to ≤10 parts by weight of the solids content of the coatingcomposition, and (d) at least one organic solvent, comprising a mixtureof 1-methoxy-2-propanol and at least 50% by weight of diacetone alcohol,where the proportion of ethylenically unsaturated groups is at least 3mol per kg of the solids content of the coating composition, and apartial metal coating or a metal layer on the coated surface.
 2. Thecoated film as claimed in claim 1, comprising a polycarbonate film or acopolycarbonate film.
 3. The coated film as claimed in claim 1, whereinthe acrylonitrile-butadiene-styrene copolymer (a) has an acrylonitrilecontent in the range from ≥20% to ≤30%.
 4. The coated film as claimed inclaim 1, wherein the acrylonitrile-butadiene-styrene copolymer (a) has apolybutadiene content in the range from ≥10% to ≤16%.
 5. The coated filmas claimed in claim 1, wherein the acrylonitrile-butadiene-styrenecopolymer (a) has a Vicat softening temperature VET to ISO 306 of atleast 95° C.
 6. The coated film as claimed in claim 1, wherein the atleast one UV-curable reactive diluent (b) comprises bifunctional,trifunctional, tetrafunctional, pentafunctional and/or hexafunctionalacrylic and/or methacrylic monomers.
 7. The coated film as claimed inclaim 1, wherein the metal layer comprises at least one metal selectedfrom the group consisting of tin, lead, silver, gold, palladium,platinum, cobalt, manganese, bismuth, copper, nickel, iron, chromium andmixtures thereof.
 8. A method comprising utilizing the coated filmcoating composition as claimed in claim 1 for the production of 3Dmouldings for the automotive, transport, electricals, electronics andconstruction industries in a film insert moulding process.
 9. A mouldedcomponent comprising at least one coated film as claimed in claim
 1. 10.The coated film as claimed in claim 1, wherein theacrylonitrile-butadiene-styrene copolymer (a) has an acrylonitrilecontent in the range from ≥20% to ≤30%, and wherein theacrylonitrile-butadiene-styrene copolymer (a) has a polybutadienecontent in the range from ≥10% to ≤16%.
 11. A process for producing thecoated film as claimed in claim 1, comprising the steps of: (i) coatinga film with a coating composition having a solids content and a contentof ethylenically unsaturated groups comprising (a) at least onethermoplastic acrylonitrile-butadiene-styrene copolymer in a content ofat least 30% by weight of the solids content of the coating composition,wherein the acrylonitrile-butadiene-styrene copolymer has anacrylonitrile content in the range from ≥19% to ≤35%; (b) at least oneUV-curable reactive diluent in a content of at least 30% by weight ofthe solids content of the coating composition; (c) at least onephotoinitiator in a content of ≥0.1 to ≤10 parts by weight of the solidscontent of the coating composition; and (d) at least one organicsolvent, comprising a mixture of 1-methoxy-2-propanol and at least 50%by weight of diacetone alcohol, where the proportion of ethylenicallyunsaturated groups is at least 3 mol per kg of the solids content of thecoating composition; (ii) drying the coating; (iii) optionally cuttingthe film to size and/or printing and/or thermally or mechanicallyforming the film; (iv) irradiating the coating with UV radiation to curethe coating; (v) coating the cured coating with a metal coating.